Occasionally I come across mentions of old (1800s) passenger cars with 8 axles and I was wondering if anyone could point me to more information about them. How common were they, when were they made, why were they made, etc.
The only one I've seen a picture of is the Lincoln funeral car, and that seems to use a span bolster arrangement, and I'm guessing the others do as well.
If you're seeking more information, I recommend White's "American Railroad Passenger Car".
I've got his freight car book, and it is very very good. I am sure the passenger one is, too.
Ed
7j43kIf you're seeking more information, I recommend White's "American Railroad Passenger Car"
I'll second that recommendation.
In it the author states that Pullman built at least twenty-three sleeping cars with the eight axle configuration. The Burlington also constructed cars in their Aurora, Ill shops through the 1870's with a sixteen wheel design. The last ones being built in 1879.
PullmanTruck2 by Edmund, on Flickr
Here is the patent drawing for the 1867 C.F. Allen truck.
PullmanTruck1 by Edmund, on Flickr
Unlike the Lincoln car these do not use a span-bolster.
Good Luck, Ed
gmpullman Unlike the Lincoln car these do not use a span-bolster.
Interesting truck. It appears to me that it "sorta" has a span-bolster, in that it has two external span-bolster-like thingys, rather than one internal one.
Examining the artist's interpretation, it's interesting that there's no kingpost in the truss that makes up the semi-span-bolster. As opposed to the patent drawing.
7j43k It appears to me that it "sorta" has a span-bolster, in that it has two external span-bolster-like thingys, rather than one internal one.
Studying the plan view clears up your suspicions! A clever design, indeed...
Pullman_8_plan by Edmund, on Flickr
Regards, Ed
OK, I did get a chance to look at the book, and covers the subject pretty well. Looks like the answer to why is that designers figured since there was such a large improvement in ride quality going from 2 axles to 4, then going to 8 must be even better, when in practice it ended up being worse.
Decades ago MR reprinted some drawings of various "experimental" PRR locomotives, including an 0-8-0 of an extraordinary rigid wheelbase which even in its own time was said to be unequaled in its tendency to attempt to find the shortest route over sharp curves.
I suspect the perceived theoretical advantages of 8 axle passenger cars similarly fell by the wayside. As a 20th century railroad executive once said, nobody likes to see a murder but it is particularly sad to see the murder of a beautiful young theory by a nasty gang of facts.
Dave Nelson